9. Lobular hyperplasia
Ductal hyperplasia with ducts growing out radiating centrifugally. These lesions develop in mouse strains carrying MMTV-P (eg, RIII, GR) during pregnancy. They can become relatively large (1 cm) and regress after the mouse has given birth. Also referred to as 'plaque', 'organoid tumor', pregnancy-dependent tumor', 'Type P tumor', adenocarcinoma type B